1. Field of the Invention
The present invention relates to a medicament containing at least one compound selected from the group consisting of sulfopyranosylacylglycerol derivatives and pharmaceutically acceptable salts thereof, as an active ingredient.
2. Description of the Related Art
Sulfur-containing glycolipids contained in natural products derived from, e.g., algae and higher plants are known to have physiological activities.
For example, in a document of Ohta et al. (Chemical & Pharmaceutical Bulletin, 46(4), (1998)), it is described that a specific sulfoquinovosyldiacylglycerol derivative derived from red algae, Gigartina tenella, exhibits not only inhibitory activities against DNA polymerases α and β of higher organisms but also an HIV-derived reverse-transcriptase inhibitory activity. The sulfoquinovosyldiacylglycerol derivative disclosed in the Ohta document is the one whose fatty acid that bonded, through ester-bond, at the C1 carbon atom of the glycerol is an unsaturated fatty acid having 20 carbon atoms with 5 double bonds, and whose another fatty acid that bonded at the C2 carbon atom of the glycerol is a saturated fatty acid having 16 carbon atoms.
Furthermore, in a document of Mizushina et al. (Biochemical Pharmacology 55, 537-541 (1998)), it is described that a mixture of specific sulfoquinovosyldiacylglycerol derivatives derived from a pteridophyte exhibits inhibitory activities against a calf DNA polymerase α and a rat DNA polymerase β, however, the mixture has no effect upon an HIV-derived reverse-transcriptase activity.
On the other hand, in a document of Sahara et al. (British Journal of Cancer, 75(3), 324-332 (1997)), it is described that a fraction of sulfoquinovosylmonoacylglycerols contained in an acetone extract from a sea urchin intestine exhibits anticancer activities in-vivo and in-vitro. However, the sulfoquinovosylmonoacylglycerol fraction for which Sahara found the anticancer activities principally contains sulfoquinovosylmonoacylglycerol having, bonded thereto through an ester-bond, a saturated fatty acid with 16 carbon atoms. In the sulfoquinovosylmonoacylglycerol fraction, sulfoquinovosylmonoacylglycerols whose acyl moiety is that of an unsaturated fatty acid, are contained only in an extremely small amount. In addition, Sahara et al. have not yet investigated on anticancer activities with respect to individual components contained in the sulfoquinovosylmonoacylglycerol mixture.
Furthermore, National Patent Publication No. 5-501105 describes that a sulfoquinovosyldiacylglycerol derivative has an anti-virus activity. More specifically, it discloses that the derivative has an anti-HIV (human immunodeficiency virus) activity, however it does not disclose that the derivative has DNA polymerase inhibitory activities and anticancer activities.